[TSM330i]

I thought I'd email Autothority (best known for tuning Porsches) to see if they had a tune for our cars. Here was their response:

Hello,
Yes we do, you can expect about 20 hp gain and cost is $795.00.
ECU must be sent in to us for programming and turn around with in 24 hr
Regards,
Min

They are a respected tuner for sure. It doesn't appear that there are many alternatives out there for us. Personally, I'm not in the market to upgrade HP, but the opposite - brakes. When you track your car, typically the last thing you do is add HP, suspension and brakes will get you farther than a HP increase.